title: ABI2, a second protein phosphatase 2C involved in abscisic acid signal transduction in Arabidopsis.
abstract: The abi2-1 (abscisic acid insensitive) mutant of Arabidopsis thaliana shows abscisic acid (ABA) insensitivity with respect to seed germination and vegetative ABA responses. We identified the ABI2 gene by a combination of positional mapping and homology to ABI1. The ABI2 protein shows 80% amino acid sequence identity to ABI1, a protein phosphatase 2C (PP2C) involved in ABA signaling. The mutation that confers the abi2-1 phenotype is equivalent to the mutation previously identified in abi1-1 and the resulting Gly168Asp abi2 protein shows a reduced PP2C activity. Thus, a pair of highly homologous PP2Cs regulate ABA signaling.
authors.affiliation: TU-München, Lehrstuhl für Botanik, Munich, Germany.
authors.forename: P L
authors.initials: PL
authors.lastname: Rodriguez
authors.forename: G
authors.initials: G
authors.lastname: Benning
authors.forename: E
authors.initials: E
authors.lastname: Grill
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D008969:Molecular Sequence Data; D010749:Phosphoprotein Phosphatases / Q000235:genetics* / Q000378:metabolism; D054648:Protein Phosphatase 2; D000071636:Protein Phosphatase 2C; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D029701:Saccharomyces cerevisiae Proteins; D000040:Abscisic Acid; C087434:ABI1 protein, Arabidopsis; C106443:ABI2 protein, Arabidopsis; C087358:PTC1 protein, S cerevisiae; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2; D000071636:Protein Phosphatase 2C